This invention relates to an automated imprinting system for imprinting identification code on individuals or articles such as automobiles produced in quantity, particularly on an assembly line, and more particularly to the preclusion of incorrect imprinting during operation of the system.
A system according to the invention is of use in the production of various kinds of articles, but the assembly of automobiles on an assembly line will be taken as a typical example in the following description.
At present it is usual that automobiles of various types and/or models are assembled on a single assembly line in an irregular order. The assembly operation includes a step of stamping or imprinting identification number or code on each of the half-assembled car bodies with alteration of identification code for each individual. The identification code consists of several components which respectively imply the type, model, serial number, etc. and is necessary to the registration of the manufactured cars in government offices.
In a production program a specific identification code is assigned to each individual car to be assembled on an assembly line, and the order of assembling cars of various types and/or models on the same assembly line is indicated by an arrangement of identification codes for all cars in the production program. According to a traditional method, the arrangement or setting of imprinting types of a stamping machine is altered manually for each car on the assembly line. This method is unfavorable to the productivity since an operator of the machine needs to refer to a copy of the production program to accomplish each alteration procedure. Currently, therefore, use is made of an automated stamping machine which has the ability of altering the setting of the imprinting types in response to an electrical signal representing an identification code to be imprinted next. The imprinting step is eased by this method. However, there is a possibility that the automated type-setting mechanism functions erroneously or that the electrical signal does not accurately represent an intended identification code because of, for example, malfunction of a tape reader used for producing the signal. Accordingly a worker must confirm the arrangement of the imprinting types after each action of the automated type-setting mechanism since it is very important to preclude the occurrence of an incorrect imprinting. The imprinting of an incorrect identification code on a half-assembled car will introduce confusion to the workers on work spots downstream of the imprinting spot. Moreover, there is a chance that a car component such as an engine of an unintended type or model is installed on the incorrectly marked car. In addition, there is a possibility that two cars are registered to a government office under the same identification code as the result of an incorrect marking since the imprinting of identification code is usually done also on a copy tape which is submitted subsequently to a government office. Correction of such erroneous registration requires troublesome proceedings.
From a different point of view, it may not be expected that cars (or their parts) of various types or models are conveyed along the assembly line always in the order according to the production program. Accordingly a worker on the imprinting spot must confirm that each half-assembled car arrived at the imprinting spot is of an intended type and model and that the car to be imprinted and the identification code set in the imprinting mechanism are in accordance with one another.
From the above described reasons, it is rather difficult to say that the employment of an automated imprinting machine has produced a substantial improvement in productivity.